A pylon is a connection interface of an aero-engine and an airfoil and mainly functions to mount the engine, transfer engine load, provide a pathway for systems such as a wiring system, environment control system, electrical system and hydraulic system between the engine and the airfoil, and ensure a smooth aerodynamic shape. The design of the pylon structure should take into account various factors such as noise, weight, fuel consumption rate, aerodynamics, system deployment, and engine installation and maintenance.
As shown in FIG. 1, a pylon 10′ in a conventional configuration is usually designed as a rigid box-shaped structure consisting of an upper beam, a lower beam, a frame having a plurality of vertical stations, and a sidewall which are connected to one another, and assembled with the engine via a front installation joint 20′ and a rear installation joint 30′. The total load of the engine is transferred via the front installation joint and the rear installation joint, and torque is usually transmitted by virtue of the rear installation joint 30′.
The pylon in the conventional configuration transmits torque via the rear installation joint 30′. To have an enough long arm of force to transmit torque, the rear installation joint 30′ must have a larger width, which causes the shape of a rear edge of the pylon wider, affecting aerodynamic performance of the aircraft. Besides, the front installation joint 20′ is an individual component independent from the pylon but connected to the pylon, and the whole engine installation structure is heavy.
The conventional pylon is hingedly connected to a nacelle. As shown in FIG. 2, a pylon sidewall 11′ is provided with thrust reverser cowl hinges 12′ and fan cowl hinges 13′, wherein the thrust reverser cowl hinges 12′ are connected with a thrust reverser cowl body (not shown) via a guide rail beam (not shown), and the guide rail beam is provided with a guide rail for guiding the thrust reverser cowl body.
A conventional aircraft engine duct auxiliary structure for rectifying external ducted airflow is located between a nacelle external duct and a nacelle core cowl body and is connected together with the nacelle core cowl body, and is opened along with the core cowl body upon servicing. It can be seen that the conventional engine duct auxiliary structure is a design integral with the nacelle and turns out to be a component of the nacelle.